Java Interpolator

Interpolator.java

package interpolations;

public class Interpolator {
	public static final Interpolation LIN = x -> x;
	public static final Interpolation SQR = x -> LIN.interpolate(x) * x;
	public static final Interpolation CUB = x -> SQR.interpolate(x) * x;
	
	public static final Interpolation EXP = x -> Math.pow(2, x) - 1;
	public static final Interpolation LOG = x -> Math.log(x + 1) / Math.log(2);
	
	public static final Interpolation COS = x -> -0.5 * Math.cos(Math.PI * x) + 0.5;

	public interface Interpolation {
		/**
		 * @returns a y value between 0 and 1 for a given x value between 0 and 1
		 */
		public double interpolate(double x);
		
		public default double interpolate(double xMin, double xMax, double yMin, double yMax, double x) {
			return interpolate((x - xMin) / (xMax - xMin)) * (yMax - yMin) + yMin;
		}
		
		/**
		 * @return modyfies the function where f(0) = 0 and f(1) = 1 so that f(xMin) = yMax and f(xMax) = yMax
		 */
		public default Interpolation range(double xMin, double xMax, double yMin, double yMax) {
			return x -> interpolate((x - xMin) / (xMax - xMin)) * (yMax - yMin) + yMin;
		}
		
		/**
		 * @return modyfies the function where f(xMin) = yMax and f(xMax) = yMax so that f(0) = 0 and f(1) = 1
		 */
		public default Interpolation trim(double xMin, double xMax, double yMin, double yMax) {
			return x -> (interpolate(x * (xMin - xMax) + xMin) - yMin) / (yMax - yMin);
		}
		
		public default Interpolation advt() {
			return x -> interpolate(x) * x;
		}
		
		public default Interpolation slope(double slope) {
			return x -> interpolate(x) * slope;
		}
	}
}